This article discusses the architecture model and characters of the 2G/3G/LTE/WLAN network
and describes the non-seamless off-load solution of the I-WLAN network and SAE network.It solves the problem that UE can not keep the packet data service between 2G/3G/LTE and WLAN network
providing smooth evolution to seamless WLAN offload using I-WLAN and SAE.